In a typical database system supporting SQL (Structured Query Language), table rows can include one or more fields that are user defined type (UDT) fields. One type of UDT is a UDT structured type. The UDT structured type shares many properties in common with the C-language “struct.” Both a C-language struct and a UDT structured type can be declared to be composed of any number of data members which can be either homogeneous or heterogeneous with respect to their data types. Both a C-language struct and a UDT structured type can also be nested, containing data members which are themselves structured types. The declaration of a UDT structured type is entered into the DBS system using SQL Data Definition Directives. One type of UDT used to support large objects is a BLOB UDT (“Binary Large OBject”).
A typical database system tracks the age of stored data, such as by using timestamps. Data “ages” as it resides in storage without being accessed or used. Typically, the database system periodically evaluates stored data and removes data from storage that has exceeded a threshold age.